Comments by damuvi (Top 1 by date)

You are right, after all this long explanation, I really didn't sumarize the problem.
In only a few words, a msgbox in an event procedure (OnBarcodeScanned) launched from the wndproc dissapears without the user intervention (as the matter of fact I don't even get to see it), but if I launch a second msgbox, this is shown correctly.
I expect this time is a bit more clear.